Health Check: why are some people afraid of heights?

If you’ve ever felt your heart race as you looked down from the top of a tall ladder, you’re not alone. But for some people, their distress is far more serious. Simply thinking about climbing a ladder can lead to intense fear and anxiety.

These are the roughly one in 15 people who have a fear of heights (acrophobia) at some point in their lives.

So, what leads some people to feel anxious even thinking about climbing the ladder? And others happily climb up onto the roof?

Read more: Explainer: what are phobias?

What is acrophobia?

About one in three people say they experience some discomfort or distress when exposed to heights. But not all of these have acrophobia. The term acrophobia is reserved for people with extreme, irrational and persistent fears of heights and situations associated with them.

It’s one of the so-called natural environment phobias, which also include a fear of thunder and lightening (astraphobia) or water (aquaphobia).

Read more: Fear of death underlies most of our phobias

People with acrophobia often avoid situations where they will be exposed to heights. However, this is not always possible.

When faced with heights or anticipating them, their sympathetic nervous system is aroused, as if preparing the body for an emergency. This arousal helps either approach or escape from a threat (commonly known as the fight-or-flight response).

They may experience vertigo (a moving or spinning sensation), increased heart rate, shortness of breath, sweating, anxiety, shaking or trembling, and nausea or an upset stomach.

Read more: Explainer: why do we get butterflies in our stomachs?

A fight-or-flight response can be adaptive in dangerous situations, because it can help us respond to dangerous situations.

But in people with acrophobia, this response can occur when no danger is present. For instance, some people are extremely distressed when thinking about heights.

There are two main perspectives about how acrophobia develops. Broadly, fears and phobias are either innate (evolutionary perspective) or learned (behaviourist perspective).

Are we born with a fear of heights?

According to the evolutionary psychology perspective, fears and phobias are innate. That is, people can experience a fear of heights without direct (or indirect) contact with heights. Instead, acrophobia is somehow hardwired so people have this fear before they first come into contact with heights.

Evolutionary psychologists suggest people who are afraid of heights are more likely to escape from this potentially dangerous situation or avoid it altogether. By doing this, they are then more likely to survive and later reproduce, allowing them to pass on their genes. Researchers suggest that as a result, this fear has been passed down from generation to generation.

But this mechanism cannot account for all phobias. Innate phobias must reflect objects or situations that have presented a long-term threat to human survival. Avoiding the object or situation must also increase opportunities for reproduction.

While the evolutionary perspective may explain phobias such as a fear of heights or snakes, it has difficulty explaining phobias associated with going to the dentist or public speaking.

Do we learn to be afraid of heights?

According to behaviourists, fears and phobias are learnt, most commonly due to what’s known as classical conditioning.

To demonstrate how classical conditioning of phobias occurs, consider the following scenario.

Imagine you climbed a tree for the first time. What is your reaction to being up a tree? According to the behaviourist perspective, you’d be unlikely to be afraid. But if you then fell from the tree, you would likely experience distress and fear.

A behaviourist would expect that because the experience of being up high is followed by the trauma of falling, you may then learn to associate the negative event with heights.

Because of these learnt associations between heights and trauma, behaviourists suggest people can then be afraid of heights in future encounters.

The behaviourist perspective also has some problems. It finds it difficult to explain why people who have never been exposed to an object or situation can report a phobia. For example there are no snakes in New Zealand, but there are people in New Zealand with snake phobias.

Behaviourists also suggest fears and phobias can also be learnt vicariously. So behaviourists suggest it may be that some people in New Zealand may have learnt their fear of snakes by hearing stories from other people with a fear of snakes.

In reality, the best explanation may be a mix of both behaviourist and evolutionary perspectives.

Can it be treated?

In treatment, both evolutionary and behaviourist accounts draw on the behaviourist perspective of how fears and phobias are learnt.

Systematic desensitisation (or exposure therapy) is a commonly used therapy for various phobias, whether the fear is innate or learnt.

It involves gradual exposure to the feared object or situation in a safe and controlled environment. This is so that when coming into contact with the feared object or situation, people learn that they are not in danger and no longer experience a phobic response.

If this article has raised concerns for you or someone you know, please contact beyondblue for more information about phobias and how to treat them.